Cannot access WinXP taskbar in fullscreen (Ubuntu x86_64)

Description

When I put Windows XP Professional into fullscreen mode, I no longer have access to the taskbar. When I hit the exact pixel that the taskbar starts at, my cursor switches to my Linux cursor and I have no access to clicking onto it. This happens with mouse integration, and not when the VM catches the mouse on it's own, and you have to press the host key to release it. I tried disabling the absolute pointing device, and that did nothing to fix it.

This problem does not happen in Windowed mode, and I am unsure if this problem also exists running Ubuntu as the guest, or any other OS's as the guest.

I think I might've just encountered this in WINE when using fullscreen. My KDE taskbar is set to autohide, this may be causing issues with programs using fullscreen, or may even be an issue with KDE itself. This never used to be a problem with VirtualBox though, so I assume it can still be fixed here.